


'Cause all that I get isn't enough

by RedHelia



Category: Supernatural
Genre: Alpha!Dean, Alpha/Beta/Omega Dynamics, Come Marking, M/M, No penetrative sex, PWP, Sam's 13, Sharing a Bed, Unbeta'd, Underage - Freeform, Weecest, handjobs
Language: English
Status: Completed
Published: 2020-03-05
Updated: 2020-03-05
Packaged: 2021-03-12 21:49:21
Rating: Explicit
Warnings: Underage
Chapters: 1
Words: 3,600
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/23025466
Author URL: https://archiveofourown.org/users/RedHelia/pseuds/RedHelia
Summary: The night Dean presents as an alpha he's in pain and confused, Sam is his only comfort.This work is unbeta'd.
Relationships: Dean Winchester/Sam Winchester
Comments: 28
Kudos: 146





	'Cause all that I get isn't enough

Dean presents as alpha a few months after his seventeenth birthday. 

Its the middle of the night when Dean's awoken by a sharp pain in his gut and he knows immediately what it is. Knows he should run far and fast. He'd heard the stories, had all the nightmares but its too late now. He can't physically do anything but curl tighter into himself as his lower body begins to sting and burn. Sweat beads across his forehead as he strains to make himself sit up.

Sam stirs beside him. Dad's away on a hunt but funds had been tight when he left so Dean had moved them to a smaller room with just the one bed. Sam's 13 now, much too old to be sharing with his big brother, but he hadn't put up a fuss. Now Dean sort of wishes he had. 

Cramps seize through his abdomen and settles low, spiking hot and knife-sharp around his balls forcing a half-groan half-sob out of him. He feels cold and feverish at the same time, teeth chattering even as his shirt grows damp with sweat,

"Whassit?" Sam asks muzzily, tousled head emerging from the covers to peer blurrily up at Dean. 

"Hurts, Sammy," Dean grunts out, squeezing his knees together in an attempt to ease the pain. 

Sam turns to face him fully and looks at him more closely, eyes puffy from sleep and far too serious for such a young kid. He sniffs delicately at the air and his nose wrinkles at the musky, unfamiliar odor. "Is it...are you..?" At Dean's nod, he curses and pulls Dean down to curl up against him. He breathes deep at Dean's hair, at his neck, warm puffs of breath dragging goosebumps along Dean's burning skin as he searches for the scent he'd always known. But Dean's now reeking with the new pheromones being pushed out with his sweat. 

"Alpha," Sam says decisively. 

Dean feels a surge of pride at the word. Alpha. He can't wait to tell their dad. John had often mused about his boys presenting as alphas, how proud he would be to have raised and trained up a pair of alphas as hunters. And he might've mentioned how convenient it would be to not have an omega to worry about a time or two.  
The searing pain in his groin makes sense now. His knot is forming, ready to swell up and breed. 

He realizes vaguely that he's hard, cock throbbing in time with his heartbeat despite the agony lancing through his guts. Soon the pain would change over into the unbearable need to mate, 'the rut'.

He has to get out of here before he hurts Sam. 

With a grunt of determination, he struggles to get up but Sam wraps his arms tighter around him. "Let go, I have to ge-"

"Dean, if you leave now you'll hurt somebody." Sam points out, his voice shaky and scared. 

"Jesus, Sam! I'm not gonna rape anyone." Dean snaps indignantly, even as his balls began to ache as they fill and grow heavy with seed. The pain's moving away too fast and it's becoming increasingly harder to ignore the pleasurable throb in his dick. "Come on, Sammy. If I stay I could hurt you." 

"You won't. Please let me help," Sam insists, jaw set. He pushes at Dean's sweaty t-shirt until Dean gives in and lifts his arms, then stubbornly tugs Dean back into the bed. "I just want to help." 

Dean groans and lets himself be pulled down. "Okay, but if I get handsy you run and lock yourself in the bathroom. Understand?" He pants as a bolt of heat surrounds the base of his cock where the knot will form. "I-I give you permission to kick me in the balls if I try anything weird."

Sam huffs a nervous laugh. "Okay, Dean. Promise." 

Dean buries his face in Sam's hair, the scent soothing and familiar and the alpha inside purrs and calms. 

Sam is still too young to present, too young to put out pheromones and Dean is so damn grateful. If his brother had smelled of anything else he's not sure what he would do.  
He remembers sniffing omega tail at school, how good and sweet the scent had been but it had been a distant sense, he knows if he caught a whiff now he would completely lose his control. As it is, just thinking about it has him unconsciously rutting his hips up into Sam. 

Sam shifts in discomfort and moves his knee up between Dean's legs to give him something to push against. His cool hands pet Dean's back and shoulders, soothing broad sweeps and soft, gentle scritches until Dean starts pumping his hips eagerly, huffing harsh breathes against Sam's hair.  
The scent of new alpha is nearly overwhelming, and Sam has to struggle with himself not to submit in ways he never will for their father. 

"It's okay, Dean." Sam shushes, petting Dean's hair comfortingly while his brother humps his leg with abandon.

Dean hisses harshly as his knot finally pops, the surge of relief and pleasure so great he thinks he's going to blackout, but it's not enough to make him orgasm, not yet. He needs...just a bit more. He grinds his swollen prick hard against his baby brother's thigh, grunting as he presses harder, riding until the head is pushed up tight into the groove of Sammy's soft little hip. 

His boxers are wet and starting to chafe uncomfortably and he huffs out a breath of frustration, hands that he'd been trying so hard to keep to fisted in the blankets suddenly move of their own accord and push the constricting garment away. He looks down and catches the first sight of his new knot. It's cherry red where the skin is stretched taut and shiny, beginning to purple and swollen to the size a softball and he can hardly believe the reality of it. He's expected to put that inside of someone. How was it even physically possible? 

Sam gasps softly. "Wow," he breathes and Dean's cock jumps, precum dripping at the thought of an audience. 

Sammy's seeing this for the first time as well and if Dean were in his right mind he would make Sam go hide in the bathroom, wouldn't let him see. He's still just a child, for fuck's sake. But Dean's not in his right mind. The new alpha part of himself has nearly full control now and it likes that Sam is watching, likes that his innocent Sammy is the one to be so impressed by the swelling of his knot, likes that the boy will know his place and _oh god_, Dean can't let it think like that. 

Somewhere deep in his head, Dean prays Sam will be alpha too, but the beast argues that it won't matter. He will always be the oldest, the strongest, always be dominant. 

Sam's hand twitches forward, reaching to touch but stopping himself in time. "Can I-Does it hurt?" So damn innocent.

The alpha growls, a thick rumbling sound pouring from Dean's throat and Sam looks up to meet his gaze, wide-eyed and puppy-faced in a way that nearly has Dean forgetting that Sam's still a kid. 

"Not anymore," he grits out, sliding the palm of his hand over the swollen shaft. "Just aches, but it's good," he hisses, thumbing at the throbbing head, the slit leaking a steady trickle of precum. He aims it at Sam's baby-soft thigh and bites down hard on his lip as the precum creates a smooth, slippery slide up and he watches in fascination as the thick head disappears under the edge of his brother's worn boxer shorts.  
It's the hottest thing he's ever seen and his inner alpha growls it's agreement. 

Sam sighs and presses closer. "Wow, it's so warm, De." 

Dean tilts his head and smiles, predatory and calculating. He pulls back and ruts back in, savoring the slick glide of it, eyes never leaving Sammy's reddening face. His free hand, mind of its own, pushes up the thin t-shirt Sam's sleeping in and seeks out the soft, warm skin of his belly.

Sam jumps at the contact and looks up in confusion but allows it when Dean starts shifting around, doesn't protest when his brother pushes him flat onto his back and straddles his hips. He should run, should listen to Dean's earlier warning to go and hide away until it's over but Dean's hot and feels so good pressing against him, and even though his heart feels like it's going to beat out of his chest it's the best thrill he's ever had. 

Dean guides his cock to smear over his brother's smooth stomach, drooling head catching in the belly button and filling the tiny divot with precum until it pools and slips down in a shiny trail. 

Okay, correction: _that's_ the hottest thing Dean's ever seen.

He moans and wonders what it would be like to fill up every orifice with his cum, pump all of his seed deep inside Sam until his brother is bursting with it, leaking and full of nothing but Dean. Until Sam is his and his alone. He's surprised at just how much he wants that, wants it so bad he can hardly breathe with it.

His knot aches and he's burning up and he needs to cum and its only Sam here. young, sweet little Sammy and Dean's going to mark him up and ruin him. He'll slip inside like a demon and wreck everything shiny and perfect about his brother, fill him up and paint his insides until there's nothing clean and pure left. The thought makes him pause, hand still wrapped tight around his dick. 

_look out for Sammy, boy_

Dad would kill him. 

His alpha doesn't care, doesn't even flinch at the thought. It would rip John apart with its bare teeth if he tried to take Sam away, no hesitation. 

_mine!_

Sam lets out a mewling noise of pain when Dean suddenly drives his cock down into his belly, poking hard into the bit of puppy fat still clinging to Sam's stomach. Dean's cock isn't small, he's thick and long, his knot adding to the length even more and just looking down at it jamming in against his gut makes Sam cringe. The thought of how full an omega would feel, of how full Sam could feel if Dean worked his way inside leaves him feeling flushed and trembly. His ass clenches instinctively.  
He's not ready for that, he's not even sure if he's going to be an omega or alpha and Dean definitely doesn't want Sam like that. Not really. This is all just hormones, something Dean can't control. 

But right now, Dean is heavy and so, so warm in his lap, his head thrown back to gaze unseeing at the waterstained ceiling, mouth open and panting. Dean rocks his hips desperately against him and despite the pain, Sam's never seen his brother look more beautiful. He's too young to get really hard but he knows Dean can feel the way his young cock has begun to heat and pulse where he's pressing against his heavy balls. 

"Ca-can I touch you, Dean?" he asks, embarrassed but needing to stop Dean from bruising his stomach. "I wanna help." 

The alpha grabs Sam's hand and wraps it around his shaft before Sam's even finished asking and before Dean knows it he's got both of Sam's smaller hands working up and down, precum making everything slippery and _so fucking good_, his own hand pressing at the knot, pushing and squeezing at the aching mass. They work at it together, driving Dean closer and closer to orgasm. Sam's half-hard chub ruts up into the space behind Dean's cum-heavy balls, perilously close to his hole and the alpha doesn't like that at all, the dominated feeling almost overwhelming but Dean doesn't mind the added stimulation, knowing Sam's little cock doesn't pose a threat just yet.  
He's pushing into Sam's hands, grinding down on his young prick and its so good, so right and just this side of too fucking much. Need burns through him like lava and he's going to come soon, going to finally shoot his alpha load for the first time and his Sammy is here and everything is perfect. 

Sam cries out in surprise as his orgasm hits, the heady scent of alpha and the pressure against his groin enough to drive the high breathy sound out of him as he jerks and curls in on himself, half sitting with his much larger brother on his lap as he cums dry. 

Dean's knot swells even more as Sam's hands tighten around his shaft, but it's the squeaky sound of Sam's pleasure that pushes him over, has him roaring out his own climax like a dying man. His free hand comes up to clutch at the back of his little brother's neck dragging him even closer as his cock releases the first spurt of seed. He throws his head back, hips still working eagerly, chasing that high as he pumps more and more cum all over his Sammy, marking him, drenching him in the scent. 

_mineminefuckingmine_

Sam's face is pressed tight against Dean's chest, held there by Dean's hand too tight on his neck, nails breaking into the tender skin there but he can't bring himself to complain. He can only gasp in shock as he's covered with a hot splash of Dean's cum but he doesn't remove his hands. It hits his chin and neck, paints his chest white and the scent is so thick and pure alpha sex that he grows dizzy with it. 

Dean's body, taut and stiff as he pours himself out, suddenly relaxes and sags down against Sam, who can barely hold him up, and lets himself be guided down to his side of the bed, cock still pulsing weakly, pumping out thin ropes of cum in hot little spurts. 

"God, there's so much." 

At Sam's disgusted little voice Dean peeks one eye open and gets a good look at his brother. 

Sam's hair is a mess, sticking up at odd angles, his t-shirt is rolled up under his armpits and clinging to his skin with sweat and cum. White, pearly streaks of jizz drip from his chin and chest to pool in his lap and soak his boxers and the bedclothes. He looks thoroughly debauched. 

Dean laughs while his alpha crows happily. 

Sam starts to get up but Dean catches his arm and drags him back down into the ruined bed. "Not yet." he pulls Sam against him, his cock giving another weak spurt that soaks into the back of Sam's already sticky-wet underpants. 

The younger boy struggles. "No, Dean! I have to shower, I have school tomorrow-" 

"No, you don't, I'll write you a note okay? Give it a minute." His hand slicks down Sam's chest, cooling cum slippery under his fingers as he rubs it into Sammy's skin. "Just a minute." His instinct is telling him to bite, to mark permanently, make it known to all that Sammy is his and everyone else can back the fuck off, but he won't. He would never do that to a kid, and definitely not to Sam. But this, he collects more jizz and rubs it higher up around Sam's neck, he can do this.

Sam grumbles unhappily under his breath, bitch-face in full force but he relents and allows himself to be pulled back down. He turns on his side and wiggles back further against Dean. 

Dean's new alpha instincts seemed to be very primal, and pretty damn territorial if the way Dean keeps whispering '_my Sammy, my pup, mine_' over and over between soothing licks to the sluggishly bleeding wounds on the younger boy's nape while rubbing the drying cum into a sticky lather across his abdomen and chest. 

It's starting to get cold and uncomfortable but Dean's body is a heated press against him and Sam finds himself relaxing into a smile anyway. He feels gross and he knows a freak out is coming from both of them later but right now he feels accomplished and proud of himself, of his brother. 

Finally, Dean's hold eases, a hand stilling under Sam's messy chin. A thumb slides its way over his bottom lip and Sam unthinking bites at the digit. His eyes widen a little with the burst of salt but he doesn't have time to really think about it when suddenly Dean pulls away and smacks his hip, summarily dismissing him.

Sam sighs and gets up to take a shower. "Clean up your mess, jerk," he demands, pointing at the wet and rumpled sheets. 

Dean huffs. "Eat me, bitch." 

Sam freezes in the bathroom doorway and looks back over his shoulder. Dean's staring back at him, all wide green eyes and flushed cheeks. His words sinking in and twisting, taking on new meaning. 

"You're not my- I didn't mean that, Sam. I was just--"

"It's okay, Dean," he reassures and leaves him to it. His own cheeks hot with shame and something else. 

Bitch. 

The word had been nothing to them before but now...everything is different. 

He tries picturing himself as Dean's bitch, imagines what life would be like as his brother's omega and shivers at the mental image. The brief taste of Dean lingers on his tongue and his stomach quivers though not entirely in disgust. He's known Dean his whole life, knows everything about his brother, from how loyal he is to how incredibly annoying he can be and he knows that someday Dean will make a damn good alpha. 

Irritated at his train of thought, Sam shakes his head violently and gets in the shower, turning the water as hot as it will go. He's not even sure if Dean would want to do this again. 

Under the scalding water, Sam scrubs as hard as he can, rubbing his skin raw, but the dark, musky alpha scent remains. The cuts on his neck sting under the spray and his stomach is sore where Dean pressed into him. The worst though is the way his hands still hold the pulsing, phantom weight of Dean's thick cock. He can practically still feel the heat of his knot. Sam's face burns. 

Dean's marked him thoroughly and in more ways than one.

School will be interesting. He just hopes Dad doesn't come back early.  
`  
Dean cleans up the bed, pulls the sheets off and leaves them in a heap by the door for housekeeping. The room still stinks of sex and his alpha preens, more than pleased with the potent scenting. It's futile but he cracks the window anyway. 

After fixing the thin blankets that miraculously remained dry over the stripped mattress and changing into a clean pair of boxers, he sits on the bed, heart in his throat. Guilt is starting to well up and he closes his eyes against the sting, listens to the sound of the water running in the bathroom. 

His cock begins prickling with interest again, not as urgently as before, the first wave of the rut nearly enough to drain him dry, but he can hear Sammy scrubbing away in the shower, can picture his lithe, young body dripping with water and soap, twisting and bending to get those hard-to-reach places. He groans and rubs a hand through his hair in frustration. He should be disgusted with himself, should grab his gun and free Sam from the monster he was becoming but he's not that strong. 

He stares at the closed bathroom door, waiting. He has so many questions, wants to march in there and just ask Sammy why. _Why'd you let me do this? Why didn't you push me away? Are you okay? _

_Do you want to do it again? _

The water keeps running and Dean gets jittery and impatient. He starts pacing. He's sure Sam will want to talk about this, Sam's always been the chick-flick type but the longer it takes for his brother to get out the bathroom the less control Dean feels and he's afraid he'll break down and run. Or worse, take it farther, a lot farther than a handjob and some cum dripping down his baby brother's chest. 

As it is, Dad was going to fucking kill him. 

He's so engrossed in the faded pattern of the carpet he doesn't notice the water shutting off or Sam standing by the door watching him with a soft little smile. He doesn't notice as Sam moves closer and puts himself right in Dean's path so the larger boy almost knocks him over and has to throw out his arms to steady him. 

His hands on Sam's bare skin are harder, cling tighter than he means to and they both flinch but instinct drives Dean to pull his brother closer until Sammy's wrapped up against his chest and there's nothing between them but air. 

"M'sorry," he whispers, jaw clenching with guilt even as his cock twitches eagerly against Sam's belly. He buries his nose in Sam's stupidly long, wet hair, nearly purring with pleasure at the smell of himself still clinging despite the soap Sam used. He lifts his head after a moment and looks down at his Sammy, his little brother and swears to himself that this will never happen again.

Sam pulls back and Dean's heart cracks but then Sam's fingers slot between his own and he gives a light tug.

"Come back to bed, Dean." 

end

**Author's Note:**

> I really struggled with what my first post would be and I settled on this one because A: it's a oneshot that I actually finished and have edited and re-edited 60 times in the last 2 months and I'm nearly sick of looking at it. And 2: because I am A/B/O/Underage loving trash and I didn't want to post anything that might get y'all thinking I'm innocent and fluffy. 
> 
> I hope it was enjoyable!
> 
> Comments are actual love and constructive criticism is welcome!


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